Vesicoureteral reflux (VUR) is the most common congenital anomaly associated with urinary tract infection (UTI) in children. If unrecognized and untreated it can lead to recurrent UTI and renal scarring, which in turn can be the cause of hypertension and renal insufficiency. Most cases of lower grade VUR resolve with growth, but this can take many years. Treatment remains controversial and includes observation, long term antibiotic prophylaxis and surgical correction. More recently, minimally invasive techniques for surgical correction have been developed and this has led to more widespread intervention, which may not be appropriate or necessary. Until now treatment algorithms have been based on non-randomized, uncontrolled studies or trials without statistical relevance. The RIVUR (Randomized Intervention for children with Vesicoureteral Reflux) trial was designed as a double blind, randomized, statistically relevant study, comparing placebo to long term antibiotic prophylaxis in children with grades l-IV VUR in children 1 month to 6 years of age. It is the only study of its kind. It was initially funded in 2005 and meant to be completed in 2010. After randomization, children are observed for 2 years. Protocol development and radiologic pilot studies progressed over the first 1 1/2 years;most clinical sites were activated in 2007. Radiologic imaging techniques had to be modified at a number of clinical sites to achieve diagnostic accuracy. Statistical analysis determined that 300 patients were needed in each arm to achieve adequate statistical power. Strict entrance criteria were developed, especially regarding the diagnosis of UTI and timing between the index UTI and radiologic discovery of VUR. At present fewer than 400 patients have been randomized and it is for that reason that the RIVUR trial is being extended to 2013. The Buffalo-based consortium is one of 5 clinical centers that were initially tasked to enroll 120 children each. We are just shy of that goal and we have enrolled 113 children, more than any other, clinical center. Thus, we have been asked to enroll beyond 120, which we hope to begin doing early in 2010. It is anticipated that data from the RIVUR trial will enable appropriate treatment and utilization of health care resources for children with VUR.